Wireless service providers continually try to create new markets and to expand existing markets for wireless services and equipment. One important way to accomplish this is to improve the performance of wireless network equipment while making the equipment cheaper and more reliable. Doing this allows wireless service providers to reduce infrastructure and operating costs while maintaining or even increasing the capacity of their wireless networks. At the same time, the service providers are attempting to improve the quality of wireless service and increase the quantity of services available to the end user.
The mobile switching center of a wireless network provides connections between a number of wireless network base stations and the public switched telephone network. Calls originated by or terminated at a cell phone or other mobile station are handled in the mobile station by a number of call processing client applications. A conventional mobile station typically contains a large switching fabric controlled by a main processing unit (MPU) that contains a large number of data processors and associated memories, often in the form of ASIC chips. Each of these MPU processors contains a call process client application for controlling the flow of control signals of a single call. Each call process client application in turn communicates with a call process server application that controls the flow of control signals for a large number of calls.
Thus, when a particular event occurs during a phone call (e.g., the call set-up, the invocation of three-way calling, call disconnection, or the like), control signals associated with the event are relayed from the mobile station to the call process client application in the mobile switching center (MSC). This call processing client application then relays the control signals to the call process server application, which actually performs the call processing service requested by the control signals.
It is important to keep the mobile switching center of a wireless network fully operational at all times. Typically, when a version of software in a mobile switching center must be upgraded, the mobile switching center must be temporarily taken “off line” during the time that the new software upgrade is being installed. This requires the use of a backup or substitute mobile switching center to maintain a full level of call traffic management.
Therefore, there is a need for improved wireless network equipment and services for upgrading software in a mobile switching center of a wireless network. In particular, there is a need for a system and method for providing an online software upgrade to a mobile switching center so that a mobile switching center that receives a software upgrade does not have to be taken off line during the time of the software upgrade.